Drawbar hinge for truck trailers and the like



15, 1961 H- c. HARBERS ETAL 2,996,313

DRAWBAR HINGE FOR TRUCK TRAILERS AND THE LIKE Filed Oct. 19, 1959 2 Sheets-Sheet 1 INVENTORS HEN/9V6. #4195525 52/066. #4444157- BY M f I4 ATTOQ/VEY United States Patent G 2,996,313 DRAWBAR HINGE FOR TRUCK TRAILERS AND THE LIKE Henry C. Harbers, Pasadena, and Buck C. Hamlet, La

Puente, Califi, assignors to Western Unit Corporation,

City of Industry, Califi, a corporation of California Filed Oct. 19,1959, Ser. No. 847,366

9 Claims. (Cl. 280485) This invention relates to a drawbar hinge construction for truck trailers and the like.

An object of the present invention is to provide a strong, simple and safe drawbar hinge which performs the functions of prior-art hinges, and other functions, yet which may be manufactured for approximately 50% of the cost.

Another object of the invention is to provide a drawbar hinge which requires no machining operations, and which is characterized by high strength and low weight.

Another object of the invention is to provide a drawbar hinge which is extremely simple to assemble despite variations in the relative positions of the elements, and which does not require that a pin or the like be inserted from one end to thus necessitate provision of clearance adjacent such end.

A further object is to provide a drawbar hinge which is easy to disassemble even after long periods of use under high stresses.

Another object is to provide a drawbar hinge incorporating means to hold the drawbar or tongue at a desired elevated condition for coupling with a truck, yet which does not impede operations of the hinge should such means become inoperative.

An additional object is to provide a drawbar hinge in- A corporating elastomeric bushing elements which may be for-med economically as extrusions, and which permit assembly of various parts of the hinge in different rotated positions as required by the particluilar truck-trailer assembly.

These and other objects and advantages of the invention will be more fully set forth in the following specification and claims, considered in connection with the attached drawings to which they relate.

In the drawings:

FIGURE 1 is a top plan view illustrating a drawbar hinge constructed in accordance with the present invention, a portion of one pressure plate being broken away;

FIGURE 2 is a vertical section taken on line 2-2 of FIGURE 1;

FIGURE 3 is a vertical sectional view corresponding to FIGURE 2 but illustrating the positions of the parts after the tongue has been released to permit downward pivoting thereof until the elastomeric protuberances become operative to limit such pivoting;

FIGURE 4 is a vertical sectional view taken longitudinally of the hinge, on line 44 of FIGURE 3; and

FIGURE 5 is a perspective view illustrating one of the elastomeric cushion or bushing elements.

Referring to the drawings, it is .pointed out that the hinge has only six parts, in addition to four standard bolts and the associated nuts. Such parts comprisefour' castings which require no machining, and two sections. The castings include a hinge bracketlt), a hinge pin 11, and two pressure plates 65 form the functions of cushions or bushings adapted to of an elastomeric Q extrusion.

12. The sections of elastomeric extrusion, which perlimit relative rotation between hinge pin 11 and bracket 10, are numbered 13. g

Proceeding first to a description of the hinge bracket 16 formed integrally at both ends thereof. The flanges I 10, this comprises an elongated body 15' having flanges 2,996,313 Patented Aug. 15, 1961 16 are parallel to each other and spaced a substantial distance apart, and each is formed with a recess adapted to receive a cushion or bushing member 13. Stated otherwise, each of the flanges 16 is so shaped that it forms four walls of a six-walled chamber in which each cushion member 13 is confined as will be described subsequently. The remaining two walls of each chamber are formed by the hinge pin 11 and a pressure plate 12.

Stated more definitely, the four recess or chamber walls formed by each of the flanges 16 comprise a bottom wall 17 (FIGURES 2-4), an end wall 18 (FIGURES 1 and 4), and two side walls 19 one of which is illustrated in the broken-away portion of FIGURE 1.

The hinge pin 11 is an elongated tube having end portions 21 disposed in the above-indicated recesses or chambers but spaced substantial distances inwardly from the walls thereof. The hinge pin has a central portion provided with a plurality of large-diameter annular flangesor ribs 22 two of which are disposed sufliciently close to the flanges 16 to form the opposite end walls of the above-indicated recesses or chambers. Stated otherwise, two of the ribs, numbered 22a and 22b, are disposed opposite the first-mentioned end walls 18 and form the remaining end walls.

The flanges or ribs 22 of the hinge pin 11 are integral with a connector portion 23 to which is welded or otherwise rigidly secured one of the drawbar or tongue members 24 of the apparatus. It is to be understood that the hinge bracket 10 is rigidly secured by means, not shown,

to one end portion of the front wheel bolster of the. trailer. Furthermore, a second and corresponding hinge bracket (of the second and corresponding drawbar hinge construction) is rigidly secured to the other end portion of the front wheel bolster. is associated with one of the drawbar or tongue members 24, such members converging forwardly (in a tongue) to an apex point at which is located the means for securing the tongue to the truck body. The hinge brackets 10 of the two hinge assemblies are so oriented that the hinge pins 11 are coaxial and horizontal, and are parallel to the common axis of the front wheels of the trailer. The tongue may therefore pivot upwardly and downwardly about a horizontal axis through both hinge assemblies.

The pressure plates 12 comprise generally rectangular members adapted to seat over the flanges 16 to form the top walls of the chambers containing elastomeric cushions or bushings 13. Four bolts 26 are extended downwardly through the pressure plates 12 and through suitable vertical bores in the flanges 16, being associated with nuts 27 located beneath the flanges. Tightening of durable and strong elastomer such as neoprene, and is generally tubular in shape except that it is made square; or flat on one side (FIGURE 5). Each such member 13 has a central cylindrical opening 28 the diameter of which corresponds generally to that of a tubular end portion 21 of hinge pin 11. Each opening 28 is sufficiently large that the hinge pin may rotate therein.

The squared 0r flat side of" each member 13 is indi cated at 29, and is adapted to be disposed beneath a pressure plate 12.

It is an important feature of the invention that means are provided on each pressure plate 12, recess bottom: wall 17, and hinge pin end 21 to effect deformation of extrusion of elastomeric material 13 in such manner as to form deformed portions 31 adapted to limit rotation of the hinge pin 11 relative to the bracket 10. Such means comprise frusto-conical protuberances 32 formed inte- Each of the drawbar hinges pressure plate 12 due to tightening of the fastener as;-

semblies 26-.2 7, the portions 31 of elastomeric material Will be deformed or extruded into the openings 33. as shown in FIGURES 2-4.

It is emphasized that there is ,a substantial distance between the inner surfaces of protuberances 32 and the exterior cylindrical surface of each pin end portion 21,

so that. a relatively large mass of 'elastomeric material is: This is important not only to disposed therebetween. the strength of the assembly, but to permit the rubber to be deformed circumferentially as well as radially-inwardly as will be described subsequently with relation to FIGURE 2.

Operation it" is merely necessary'to-positionelastomeric cushions 13' on'the pinend portions 21, and then dispose such rnem bers in theabove-defined-recesses or chambers in flanges 16. This assembly operation is so conducted that the squaredzportions 29-of the-cushions 13- are disposed upwardly. It is pointed out, however, that the tongue'may' at this timebe rotated to any-elevation without causing rotation of the cushions 13 since the pin ends 21 may rotate inopenings 28; Let be'assumed'thatit is desired that the tongue be approximately ina horizontal'planewhen the trailer is coupledwith the-truck, although it is to be understood that-theparts may be'so assembled that the tongue, will be in-substantially-any plane: The cover plates 12; bolts- 26 and nuts 27 are then loosely assembled, and thetongue-is inclined upwardlyfrom thehorizontal as indicated in FIGURE'Z. The bolts-26 and nuts 27 aretl1'en tightened to force all of the pressure plates 12' downwa-rdly to the illustrated positions. Since each of" the cushions orbush'ings 13 is confined as stated previously, downward movement of the cover-plates'causes extru sion of portions-of the rubber into the openings'33 in pin end-portions 21. As illustrated'in' FIGURE 2, such extrusion results in creation-of substantial deformed portions 31- despite the fact that theprotuberances32 are not directlyopposite the openings 33.

The- Weight of thetonguemay then bereleased', which causes downward gravitational pivoting of the tongueto the position shown in F-IGURE 3.- The shear forces thus,

generated in-the cushionsd3-adjacent deformed'portions 31-cause'the tongue to remain substantiallyhorizontal, as shown in FIGURE 3, though it is not supportedin any manner except'by the deformed portions 31 and related parts. It is thus possible fora single operator to couple,

a truck with the tongue. V

From the above it will be understood that the hinge pins. 11 may be assembled with the hinge brackets in. a highly simple manner, without requirement that the parts be preciselylocated, and without requirementithat a pin be inserted throughbne end ofeach bracket: It; igthercfore, unnecessary to provideclearanceroom ad lacentgthe ends, of-the. brackets. 'If-it is desired-to-dis-- assemble-a hinge assembly, it is--merely necessary=to-re-- move/the fasteners 26w-27 and cover plates 22; and

, desired: This-is to be contrasted with-certain-constnuc pry the hinge pin 11 upwardly so that the cushions 13 spring out of the recesses in flanges 16.

Should it occur that the deformed portions 31 shear off, the function of the hinge assembly in coupling the trailer to the truck is not impeded in any way, and the safety of the hinges is notmdiminished. Furthermore, such shearing of the deformed portions; 31' does not tend to prevent pivotal movement of the tongue upwardly when tionswhich, when-they malfunction, not only; do not support the tongue. above-the ground burtendtoprevent'upward pivoting of the tongue to a substantially horizontal plane.

Itis emphasized that, in -service,.-the cushions 13. perform important functions of eliminating shocks,.reducing wear and noise, etc. Since they are extrusions and not molded parts, they are extremely economical and may be replaced with very little effort, as stated above.

With reference to the following claims, the termrecess shall be construed to include opening, and vice versa, with relation to elements 33 or equivalents thereof.

Various embodiments of the present invention, in addition to what has been illustrated and described in detail,,may be employed without departing from the scope oftlie accompanying claims.

We claim:. 7

1'. Adrawbar hinge for truck trailers and the like, comprising a cast metal hinge bracket adapted to be secured to a trailer, said bracket having spaced flanges disposed opposite each other, each of. said flanges being shapedto define thev bottom wall, the opposed endwalls and two side Walls of a chamber, the inner endwall and the. top wall of said chamber being open, a T'-shaped cast metal hinge member having end portions extending into said' chambers through. said open inner end walls. thereof, said end' portions ofsaidhinge member having radial recesses formed therein, the center portion of said hinge member having enlarged wall means adapted to close substantially said inner end walls of said chamber, said center portion of said'hinge member being. adapted to beconnected to'a portion of a drawbar, elastomeric extrusions mounted around said end portions of said hinge member in said chambers and abutting saidwalls of said chambers, pressureplates disposed over said top walls of said: chambers and having inwardly-extending pr'otuberanccsdisposed outwardly from said recessesin' said hinge member end-portions, and fastener means to secure said pressure plates to said hinge bracket and-to force. said pressure plates inwardly and thereby effect extrusion ofportions of-saide1astomeric extrusions into said recesses inthe ends of said hinge member.

I. The invention asclaimed in claim 1, in which the outer portions of the ends of said hinge member are spacedsubstantial distances inwardly from said protuberances; thereby permitting extrusionv of elastomeric material into said. recesses despite substantial offsetting between said end portions, and said protuberances.

3'. A drawbar supporting hinge adapted to be attached between a towed vehicle and the drawbar thereof, said hinge comprising a pair ofmain castings the first of which is adapted'to be rigidly secured to an endof a towed vehicle and the secondof which is adapted to be rigidly. securedtto the adjacent .end of a drawbar used to tow the vehicle, the first casting being generally rectangular. in shape and open along one ofits longer lateral faces and centrally of an adjoining longer lateral face with the two openings merging with one another at their adjacent edges, the second casting being generally T-shapedand having separate unitary elastomeric collars insertable axially over the opp osite ends'of th'ehead thereof, the collars and head 'ofsaid T-shaped second casting being insertable with a pressfit laterally through the "open facetofj said first casting with the stem of said T-shaped memberprotruding' outwardl'y through the central openingfin' the adjoining: face of 'said-first*casting, and pressure plate means for locking said assembled components firmly pressed together by pressure applied radially to said collars across the ends of said open face of said first casting.

4. A drawbar hinge assembly comprising a pair of main casting adapted to be assembled into a hinge assembly without need for machining operations, said castings including a main casting having a generally rectangular cavity opening through one longer face thereof, an adjoining longer face of said casting having an opening merging with one of the long side edges of the opening into said rectangular cavity, a T-shaped second casting having separate unitary elastomeric collars snugly seated over the opposite ends of its head portion and shaped to seat snugly within the opposite ends of said rectangular cavity with the stern of said T-shaped member protruding through the opening centrally of said main casting and lying normal to the longitudinal axis of main casting, and clamping means for holding said elastomeric members pressed tightly into the opposite ends of said cavity and gripping the opposite ends of said T-head in a manner resisting relative rotation of said two castings about the longitudinal axis of the head of said T-shaped member.

5. A drawbar hinge as defined in claim 4 characterized in that at least one of said castings and one of the cooperating non-elastomeric components of said hinge assembly have generally complementally shaped cooperating protrusions and cavities opposite axial surfaces of said elastomeric members, said clamping means being effective upon said elastomeric members to press said protrusions into said members to compress the same causing the latter to expand radially into said complementallyshaped cavities thereby interlocking the components of said hinge assembly against relative movement.

6. A joint assembly wherein the two principal components are separated :from one another by compressed elastomeric material cooperating to limit relative movement between said principal components, one of said principal components being a hollow, generally rectangularly shaped member open substantially throughout one longer face and including a notch leading therefrom centrally across an adjoining longer face, the other principal component being generally T-shaped and including a pair of elastomeric collars seated on the opposite ends of its head portion having an exterior shape complemental to that of the interior opposite end portions of said rectangular member, the head of said T-shaped member with its elastomeric collars being insertable as a unit 6 lateral-1y through the open face of said rectangular member with its stem portion extending through the notch across said adjoining face with its axis normal to the longitudinal axis of said one principal component, and means for clamping said components so assembled and for placing said collars under radial compression.

7. A joint assembly as defined in claim 6 characterized in that said pair of principal components comprise metal castings assembled together without need for machining or metal finishing operations and separated from one another by said elastomeric collars.

8. A joint assembly as defined in claim 6 characterized in that said collars are generally circular and provided with a wide flat-surfaced boss projecting from the circumference thereof adapted to lie parallel and close to the open face of said first principal component in the assembled position of the components, and said clamping means bearing against the wide flat-surfaces of said collars to compress the material thereof and to place the same under high pressure contact with the opposite ends of the head of said T-shaped member and with interior surfaces of said rectangular member.

9. A joint assembly as defined in claim 6 characterized in that surfaces of said two principal components in contact with axially disposed surfaces of said collars are formed one with radially projecting bosses and the other with similarly shaped cavities whereby the clamping of said collars in a manner placing them under radial compression acts to depress said bosses into the collars and to displace an equivalent volume of said collars thereby aiding materially in expanding other Portions of said collars into said cavities to provide effective positive interlocks between said collars and said two principal components.

References Cited in the file of this patent UNITED STATES PATENTS 1,804,958 Stebbins May 12, 1931 1,940,302 Humphrey et a1 Dec. 19, 1933 1,959,256 Zerk May 15, 1934 2,067,794 Seyferth Jan. 12, 1937 2,428,950 Weiss Oct. 14, 1947 2,467,530 Johnson Apr. 19, 1949 2,723,870 Page Nov. 15, 1955 FOREIGN PATENTS 748,096 France June 28, 1933 

